Potential control system



Oct. 13, 193,6.,- l B. s. BURKE ET Al. 2,057,512

l POTENTIAL CONTROL SYSTEM Oct. 13, 1936. B. s. BURKE ET AL 2,057,512

POTENTIAL CONTROL SYSTEM v Filed Jan. 25, 1953 2 sheets-sheet 2 wlTNEssEs; INVENToRs. 7i@ Z. Burz SZBurKe and Patented oct. 1 3, 193.6l

UNITED STATES PATENT OFFICE Po'rENTIAL CONTROL SYSTEM Application January 25, 1933, Serial No. 653,454 l v 7Claims. (CL175-312) Our invention relates, generally, to potential control systems, and, more particularly, to systems for controlling thepotential impressed on theatre lighting cricuts.

In theatre lighting control systems, it is desirable to pre-set the potential that Will be applied to the various lighting circuits during each scene of a perfomance in order that the desiredl intensity of illumination' and the desired color eifects may be produced for each scene at the will of the operator. It is also desirable to fade from one lighting effect to another in a smooth manner and it is often necessary to repeat effects, or to flash from one effect to another without passing througha number of intervening effects or scenes.

Present schemes provide for the presetting of intensities and'are so arranged that a number of ei'ects may be produced in a predetermined sequence, but al1 of the present schemes with which we are familiar are limited in their application to a ew scenes and do not permit the operator to smoothly fade from one scene to any other scene' without passing through the intervening scenes.

An objectv of our invention, generally stated, is to provide a practical system for controlling a plurality of electric circuits which will be simple and eiiicient in operation and which may be readily and economically manufactured and installed.

A more specific object oi our invention is to provide for pre-setting a plurality of lighting eects and for producing the effects in any desired sequence, either by fading or flashing from one effect to another without 'passing through any intervening effects.y

A further object of our invention is to provide a simple and economical means for presetting the potential impressed on a plurality of electric circuits.

Other objects of our invention will be eitherA explained hereinafter, or will be apparent to those skilled in the art.

In accordance with one embodiment of our invention a plurality of multi-contact relays are provided for establishing the circuits which control the energization of various theatre lighting circuits. The operation of the relays is controlled by a plurality of push-button switches Vwhich are so mechanically interlocked that only one switch will be closed at a time. The con- .tact members of the relays are so connected that, by operating the proper push-button switches, it is possible to either fade from one which:

Figures l and 2 together constitute a. diagrammatic view of a control system embodying our invention.

Referring now to the drawings, the illustrated embodiment of our invention comprises two theatre lighting circuits l0 and Il, connected across power conductors I2 and I3 which may be energized from any suitable source of alternating-current power (not shown). In order to simplify the drawings and description only two lighting circuits, with five scenes for each circuit have been illustrated, however, it will be understood that the system illustrated may be readily expanded to control as many circuits and scenes as desired.

The current in the lighting circuits l0 and il and, consequently, the intensity of illumination supplied by the lamps i4 and I5, is controlled by saturated-core reactors I6 and I1, respectively. Each of the reactors comprises two alternatingcurrent windings i8, disposed on the outer legs of the reactor and a direct-current control winding I9, disposed on the inner leg. The reactance oi each reactor and the current in the lighting circuits may be regulated, in a manner well known in the art, by varying the current in the control winding I9. The current in the control windings I9 of the reactors I6 and I1 may be lregulated by varying the grid-biasing potential impressed on electronic-tube amplifying circuits 2I and 22, respectively, as fully described in the copending application of R. D. Ross, Serial No.

450,586, filed May 7, 1930. However, the system herein described is not limited in its application to amplifying circuits ofthe type disclosed in the foregoing application but may be applied to any electronic-tube amplifying scheme utilizing potential control of the output of the tubes.

In order that a. pre-selected value of potential may be impressed on the tube circuits 2| and 22 to produce the desired illuminating effects from the lighting circuits I0 and II during any scene of a theatrical production, and that the effect may be changed either instantaneously or gradually from one scene to any other scene without passing through intervening scenes we have provided the control system herein decribed.

As stated hereinbefore, the apparatus necessary for controlling two circuits, with ve scenes for each circuit has been illustrated. If it is desired to control more circuits or scenes addi tional equipment, similar to that shown, may be supplied. The apparatus for controlling the potential im on the tube units 2i and 22, which in turn control the lighting circuits Ill and I, two pre-settable potentiometers 23 and 24, each provided with iive sliders, one for eachoftbeiivesceneswhichmaybesetupin advance. individual control potentiometers 2l and 23 by means of which each circuit may be controlled individually, change-over switches 21 and 23 for changing from pre-set to individual control, and two gang-operated potentiometer resistors or faders 23 and 30.

It will be noted that the pre-set potentiometers 23 and 24 are each provided with ilve sliders which may be set up in advance to impress the proper potential on the tube control units to produce the desired lighting effect for each scene.l By placing the five sliders on one potentiometer instead ol providing tive potentiometers, as has been done previously, a considerable saving is eiected in the amount of equipment required for controlling each circuit. The potentiometers may be readily so constructed that the sliders may be operated without mechanical interference.

In order that the operator may change from one scene to any other scene, either instantaneously or gradually, two relays are provided for each scene to be controlled. These relays are designated as 3|, 32, .33, 34 and 35, and 3|a, 32a, 33a, 34a and 35a. In addition, two relays 36 and 36a are provided for extinguishing or blacking-out" the lights of each circuit at any time. Each oi the foregoing relays is provided with as many sets of contact members as there are circuits to be controlled, which, in this instance is two.

The operation ot the relays 3| to 36 and 3io 'to 36a, inclusive, is controlled by.pushbutton switches 4| to 48 and 4|a to 46a, respectively. As shown, the switches 4| to 46 are provided with an interlock bar 4|! vwhich is so constructed that only one of the switches will be closed at a time, thatis, when any one of the switches is actuated to the closed position any other switch of the group, which has been previously closed, will be automatically released. Likewise, the switches 4|a to` 46a, which control the operation of the relays 3|a to 33a, respectively, are provided with an interlock bar 43a which is so constructed that only one switch may be closed at a time.

A master control potentiometer 41, which is connected across control conductors P and N, may be utilized to obtain group control of all circuits which are connected to it. The changeover switches 43 and 43 are provided for either connecting the pre-set potentiometers directly to the control conductors P and 'N or to the master potentiometer 41, as desired. Resistors 23 and 24 across the control conductors P and N, also assuming that the sliders on the potentiometers 23 and 24 have been pre-set to impress the proper potential on the tube units 2l and .22 to produce the desired lighting effects for each of the live scenes, the eilect for scene I. may be produced by actuating the push-button switch 4| to the closed position, thereby establishing an energizing circuit for the actuating coil of the relay 3|. 'Ihis circuit may be traced from conductor 3|, which is connected to the positive conductor P by means oi conductor i2, through conductor B3, the actuating coil oi the relay 3|, conductor 34, contact member 65 oi the switch 4|, and conductor B6 to a conductor 61, which is connected to the negative conductor N through a conductor 6I.

When the relay 3| is actuated to its closed position, circuits are established to impress a pre-selected biasing potential upon the grid cirsuits of the tube units 2| and 22, thereby controlling the current in the lighting circuits III and respectively, and producing a predetermined lighting efiect, as previously described.

The circuit for impressing a biasingv potential on the tube unit 2| extends from the potentiometer 23 through conductor 1|, resistor 5|, conductors 12 and 13, contact members 14 oi' the relay 3|, conductor 15, the arm 1B of the fader 29, conductor 11, switch 21 and conductor'lli to the tube unit 2|.

The circuit for impressing a biasing potential on the tube unit 22 may be traced from the po tentiometer 24, through conductor 8|, resistor Sla, conductors 82 and 83, contact members B4 of the relay 3|, conductor 85, the arm 36 of the fader 3U, conductor 31, the switch 23 and conductor B8 to the tube unit 22.

If it is desired to change instantaneously from scene 1 to any other scene, as `for example, scene 3, it is only necessary to actuate the pushbutton switch 43 to the closed position, which automatically releases the switch 4|, as previously explained, and also permits the relay 3l to drop to its lowermost position. When the switch 43 is closed, an energizing circuit is established for the actuating coil oi the relay 33 which extends i'rom conductor 6|, through conductor 33, the actuating coil of the relay 33, conductor 9|, contact members 92 of the switch 43, and conductor 83 to the conductor 61.

'Ihe closing ot the relay 33 establishes circuits for impressing the biasing potentials on the tube units 2| and 22 which have been previously selected by pre-setting the sliders for scene 3 on the potentiometers 23 and 24. The circuit for impressing a potential on the tube unit 2| extends !rom the potentiometer 23, through conductor 34, the resistor 53, conductors 95 and 3l, contact members 31 oi' the relay 33, conductor 93 to conductor 15 and thence to the tube unit 2| through the circuit previously traced. The circuit tor the tube unit 22 may be traced from the potentiometerv 24, through conductor IDI, resistor 33a, conductors |02 and |33, contact members |34 ot the relay 33, conductor Il! to conductor 3l and thence to the tube unit 22 through the circuit previously traced.

However, if it is desired to change gradually from the lighting eilect produced for scene 1 to the enect for scene 3, thismay be accomplished by ilrst closing the push-button switch 43a and then operating a shaft |33 to move the arms 1l and 33, d the faders 23 and 33, respectively, to tbeopposite ends of the potentiometer-resistors of the faders 26 and 30, which gradually changes the biasing potential impressed on the tube circuits from the potential Selected for scene 1 to that selected for scene 3.y

It will be noted that the switch 4| is notreleased when the switch 43a is closed, therefore, the conductors 1| and 8| remain connected to one terminal of the faders 29 and 30, respectively.

When the switch 43a is closed, an energizing circuit is established for the actuating coil of the relay 33a, which may be traced fromthe conductor 6|, through conductor |66, the coil of .the relay 33a, conductor |01, contact members |06 on the switch 43a, and conductor |09 to the conductor 61. The closing of the relay 33a connects the conductors 94 and I0| to the faders 29 and'38, respectively. The circuit to the fader 29 may be traced from the conductor 94, through the resistor 53, conductors 95 and 96, contact members III of the relay 33a, and conductors I I 2 and I I3 to one terminal of `the fader 29. The circuit to the fader '30 extends from conductor IUI, through resistor 53a, conductors |02 and |03, contact members II4 of the relay 33a, and conductors I|5 and I 6 to one terminal of the fader 3D. 1 v

After the relay 33a is closed the shaft |66 may be operated to move the arms 16 and 86, of the faders 29 and 30, to the opposite ends of the faders from those shown, thereby gradually changing the biasing potential impressed on the tube units 2| and 22 from the potential selected for scene l to that selected for scene 3. In this manner the lighting eiect produced by the circuits IU and may be gradually changed from scene 1 to scene 3 without passing through intervening scene 2.

In a similar manner the operator may change from one scene to any other scene, either instantaneously or gradually, by actuating the proper push-button and operating the faders 29 and 30. For example, if it is next desired tol flash from scene 3 to scene 5, the switch 45a" may be closed, which will release the switch 43a and the relay 33a and close the relay 351:1.,.thereby immediately impressing the potential selected for scene 5 on the tube circuits 2| and 22 and controlling the current in the lighting circuits I0 and Il, accordingly. -Or if it is desiredv to fade from scene 3 to scene 5, the push-button switch 45 may be closed and the arms 16 and 86, of the faders 29 and 36, respectively, moved back to the positions shown on the drawings, thereby gradually changing the biasing potential impressed on the tube circuits from the potential selected for scene 3 to that selected for scene 5.

If it is desired to black-ou the lights at any time, either the switch 46 or 46a, depending upon the position of the arms 16 and 86 of the faders 29 and 30, may be' closed. If the fader arms are in the position shown in the drawings, the switch 46 should be closed, and if the fader arms are at -the opposite ends of the resistors, the switch 46a should be closed in order to black-out the lights. I

Assuming that the fader arms 16 and 86 are in the position shown, closing the switch 46 will release any other of the switches of its group that may be closed and establish an energizing circuit for the actuating coil of the relay 36. This circuit may be traced from the conductor 6I, through conductor ||1, the coil of the relay 36, conductor IIB, contact members ||9 of the switch 46, and conductor |2l to the conductor 61.

When the relay 36 is closed the tube units 2| and 22 are connected directly to the negative conductor N, thereby impressing a negative bias ing potential on the tubes .which will cause the lights in the circuits I0 and I I to be extinguished. The circuit to the tube unit 2| extends from the negative conductor N, through conductors |22 and |23, contact members |24 of the relay 36, and conductors |25 and 15 to the tube unit 2| through the circuit previously traced. The circuit to the tube unit 22 may be traced from the negative conductor N, through conductors |26 and |21, contact members |28 of the relay 36, and conductors |29 and 85 to the tube unit 22 through the circuit previously traced.

In case the fader arms 16 and 86 are at the opposite ends of the resistors from that shown, a. negative biasing potential may be impressed on the tube units 2| and 22 to black-out the lights in the circuits I0 and Il by closing the pushbuttcn. switch 46a which closes the relay 36a by means of an energizing circuit which extends from conductor 6|, through conductor |3|, the actuating coil of the relay 36a, conductor |32, contact members |33 of the switch 46a` and conductor |34 to the conductor 61.

When the relay 36a is closed the tube units 2| and 22 are both directly connected to the negative bus N. The circuit for the tube unit 2| may be traced from the negative bus N, through conductors |22 and |23, contact members |35 of the relay 36a, conductor ll3, the fader arm. 16, conductor 11, switch 21 and conductor 18 to the tube .unit 2|. The circuit for the tube unit 22 may be traced from the negative conductor N, through conductors |26 and |21, contact members |36 of the relay 36a, conductor ||6, the fader arm 86, conductor 81, switch 28. and conductor 88 to the tube unit 22.

As previously stated, the potentiometers 25 and.

26 are provided to permit either of the lighting circuits to be controlled independently of the other circuit. Thev circuit I0 may be indepenently controlled by actuating the switch 21 to connect the conductor 18 to a conductor |31, thereby connecting the tube unit 2| to the potentiometer 25. Likewise, the circuit II may be independently controlled by actuating the switch 28 to connect the conductor 86 to a conductor |38, which will connect the tube unit 22 to thel potentiometer 26. The slider on the potentiometer 26 may be set at a position which will impress a potential on the tube circuit that will described is simple and flexible in operation and may be readily expanded to provide for controlling any desired number of lighting circuits and scenes.

We do not desire to be restricted to the particular form or arrangement of parts herein shown and described, since it is evident that they may be changed and modified without departing from the spirit and scope of our invention as defined in the appended claims.

We claim as our invention:

l. In a system for controlling the potential impressed on an electrical circuit, in combination, a source of electric potential, means for preselecting values of potential to be impressed on said circuit, relay means for impressing a preselected value of potential on said circuit, and means for controlling the operation of the relays to instantaneously change the potential impressed on said circuit from one preselected value to any other preselected value.

2. In a system for controlling the potential impressed on an electrical circuit, in combination, a source of electric potential, means for preselecting values of potential to be impressed on said circuit, relay means for impressing a preselected value of potential on said circuit, and manually-operable interlocked switches for controlling the operation of the relays to instantaneousLv change the potential impressed on said circuit from one preselected value to any other preselected value.

3. In a system for controlling the potential impressed on an electrical circuit, in combination, a source of electric potential, means for preselecting values of potential to be impressed on said circuit, relay means for impressing a preselected value ot potential on said circuit, manually-operable interlocked switches for controlling the operation of said relays, and means cooperating with the relays to gradualhr change the potential impressed on said circuit from one preselected value to any other preselected value.

4. In a system for controlling the potential impressed on a plurality of electrical circuits, in

pressed on an electrical circuit during a seria o( scenes of a theatrical performance, in combina tion, a source of electrical potential, means for preselecting the value ot potential to be impressed on said circuit during each of said scenes, means for selectively maldng an abrupt or a. gradual change in the potential impressed on said circuit from the preselected potential for one scene to the preselected potential for any other nonconsecutive scene, and switching means having mutually interlocked contact members for controlling the operation of the last-named means.

6.Inasystemforcontrolling thepotential impressed on an electrical circuit during a series of scenes 'of a theatrical performance, in. combination, a source of electrical potential, a single potentiometer for preselecting the value o! potential to be imprsed on said circuit during each of said scenes, means for selectively makinganabruptoragradualchangeinthepoten. tial impressed on said circuit from the preselected potential for one scene to the preselected potential for any other non-consecutive scene, and switching means having mutually interlocked contact members for controlling the operation of the last-named means.

'1.Inasystemtorcontrollingthepofential impressed on an electrical circuit during a series of scenes of a theatrical performance, in combination, a source of electrical potential, a potentiometer connected across said source, a plurality of sliders on the potentiometer for preselecting the value of potential to be on said circuit during each of said scenes, means for selectively making an abrupt or a gradual change in the potential impressed on said circuit trom the preselected potential i'or one scene to the preselected potential for any other nnuconsecutive scene and manually-operable switching means having mutually intel-locked contact members for controlling the operation o! the last-named means.

BURT 8. BURKE. CORNELIUS V. RICK. 

